FisR activates σ54‐dependent transcription of sulfide‐oxidizing genes in Cupriavidus pinatubonensis JMP134. Issue 3 (29th June 2017)

• Record Type: Journal Article
• Authors: Li, Huanjie; Li, Juan; Lü, Chuanjuan; Xia, Yongzhen; Xin, Yufeng; Liu, Honglei; Xun, Luying; Liu, Huaiwei
• Is Part Of: Molecular microbiology. Volume 105:Issue 3(2017)
• Page Start: 373
• Page End: 384
• Publication Date: 2017-06-29
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.13725
• Languages: English
• ISSNs: 0950-382X

Abstract

Summary: Some heterotrophic bacteria are able to oxidize sulfide (H2 S, HS − and S 2− ) to sulfite and thiosulfate via polysulfide. The genes coding for the oxidation enzymes in Cupriavidus pinatubonensis JMP134 have recently been identified; however, their regulation is unknown. A regulator gene is adjacent to the operon of the sulfide‐oxidizing genes, encoding a σ 54 ‐dependent transcription factor (FisR) with three domains: an R domain, an AAA+ domain and a DNA‐binding domain. Here it is reported that the regulator responds to the presence of sulfide and activates the sulfide‐oxidizing genes. FisR binds to its cognate operator at −114 to −135 bp of the transcription start of the operon. When polysulfide reacts with the R domain of FisR through the three conserved cysteine residues (C53, C64 and C71), FisR activates the expression of the operon. FisR is highly sensitive to polysulfide, activating σ 54 ‐dependent transcription of sulfide‐oxidizing genes for sulfide removal. Further, sequence analysis indicates that FisR‐type regulators are relatively common for controlling sulfide‐oxidizing genes under sulfide stress in the Proteobacteria. Abstract : Heterotrophic bacteria can oxidize H2 S to sulfite and thiosulfate with sulfide:quinone oxidoreductase and persulfide dioxygenase. Some of them use σ 54 ‐dependent transcriptional factor FisR to sense sulfide (H2 S, HS −, and S 2− ) stress and activate the sulfide‐oxidizing genes. Polysulfide, a sulfide oxidation intermediate, is the real signal instead of sulfide.